Version: 1.7.2 (using KDE 3.3.2, Gentoo) Compiler: gcc version 3.4.3 20041125 (Gentoo Linux 3.4.3-r1, ssp-3.4.3-0, pie-8.7.7) OS: Linux (x86_64) release 2.6.11-gentoo-r3 A minor bug. Settings/Configure KMail/Appearance/Headers If you have already checked the "Custom format" button, then return and edit the text entry field, "Apply" will remain shaded and "OK" will ignore the change. You must edit the text, then push another button, then push the "Custom format" button again for it to become effective.
Can not reproduce with KMail from KDE 3.5.5, can you please check if it still fails for you?
can't reproduce with kmail/KDE4 - closing